A wearable device is used by being mounted on a part of the body or clothes of a user. Such a wearable device, for example, includes a wired circuit board so as to mount an electronic element for processing electric signals.
As such a wired circuit board, for example, an elastic flexible circuit board including an insulation base material made of a thermoplastic elastomer, a wiring layer formed on the insulation base material, and an insulation layer formed on the wiring layer and made of a thermoplastic elastomer has been proposed (ref: for example, Patent Document 1).
The elastic flexible circuit board described in Patent Document 1 is produced by first, forming the wiring layer on the insulation base material and thereafter, laminating the insulation layer on the insulation base material and the wiring layer.